Up to now, there has been known an antivibration device such as a torque rod, a suspension link, or an arm of an automobile that is mounted in a vehicle and that is provided between two members to be coupled for antivibration. The antivibration device controls the relative displacement of two members while suppressing vibration transmission between the two members. As the antivibration device, for example, there is one in which rubber bushes are assembled to the both ends of the longitudinal direction of a rod, and a fluid chamber is formed at, at least, one of the rubber bushes. An equilibrium chamber whose volume is allowed to be changed by configuring a part of a wall portion using a flexible membrane is formed at an intermediate portion of the longitudinal direction of the rod, and is in communication with the fluid chamber through an orifice passage (Patent Literature 1).
According to the technique disclosed in Patent Literature 1, the fluid chamber, the equilibrium chamber, and the orifice passage are filled with an incompressible fluid, and thus the incompressible fluid flows between the equilibrium chamber and the fluid chamber through the orifice passage when vibration is input. In the case where vibration in a low vibration region (low frequency region) of approximately 10 to 20 Hz is input due to the resonant action of the incompressible fluid, a high damping force can be secured.